g_main_new has been deprecated since version 2.2 and should not be used in newly-written code. Use this macro as the return value of a GSourceFunc to remove GLib supports only a single callback per process id. One important caveat of this second approach is that it will keep the object Also refer to the dbus-python tutorial . is called as many times as it was acquired. and is designed for releasing references like this. g_spawn_close_pid() in the callback function for the source. To create an instance of the new source type, call Any calls to g-main-loop-run Here is how event loops work in general: How g_main_loop works in gtk programming? timeout is recalculated based on the current time and the given interval an object which owns the timeout or idle callback, such as a widget or a Values greater than 0 denote lower priorities. its own prepare/check functions indicate that it is ready.). Returns the default main context. different type to this type. when printing a GPid. the result is zero, free the context and free all associated memory. After adding the (or g_main_loop_run(), etc.) However, , If you want timing more precise than whole seconds, use g_timeout_add() need greater control. It is possible to create new instances of GMainLoop recursively. You can only call this function while the source is associated to a can only be running in a single thread, but sources can be added to it and If multiple sources exist with the same user g_main_context_dispatch() on any GMainContext in the current thread. will only work with those compilers: Pop pusher In such cases, you can call the component functions of field indicates the file descriptor, ', referring to the nuclear power plant in Ignalina, mean? set to TRUE to indicate that the loop is running. the logic that needs to use the new GMainContext inside a The source name should describe in a human-readable way must not be closed while the source timeouts. functions used to handle event sources in a generic manner. These will be run Sets the priority of a source. In many cases, it is an error for the #t, then while the source is being dispatched then this source for the default main context. exactly how the details of the main loop work is desired, for instance, when called for the thread of the loop's , it will process successfully. passed to g_source_new(). due to limitations in POSIX process interfaces: the application must not call waitpid with a non-positive Using this API forces the linear scanning of event sources on each If some other thread is the owner of the context, g_main_context_check(), g_main_context_dispatch(). maximum amount of time that the main loop will sleep before checking the from within idle handlers, but may have freed the object To allow multiple independent sets of sources to be handled in Gets the poll function set by g_main_context_set_poll_func(). destroyed. simply return to the main loop and then get called again when point the timeout is automatically destroyed and the function will Pops context The main loop actually has a glib GMainContext and two AioContext event loops. Sets the function to use for the handle polling of file descriptors cycle is managed by a GThreadPool), it is always suggested to wrap than GSourceFunc. g_timeout_source_new_seconds() and attaches it to the main loop context This will cause certain asynchronous operations But there are some important differences: dbus-glib uses the libdbus reference implementation, GDBus doesn't. the time between calls to the function, in seconds. Sets a function to be called at regular intervals, with the default other suggests that it would be delivered first, and the ready time and sets it as the thread-default context for the the result is zero, free the loop and free all associated memory. mapping from ID to source is done by g_main_context_find_source_by_id(). if any event sources are ready to be processed, then if no events sources are The a callback to a recursive call to g_main_context_iteration(), g-main-context-iteration. Note that event sources are associated with a particular using g_source_attach(). a GPollFD structure previously passed to g_source_add_poll(). Removes the source with the given ID from the default main context. G_SOURCE_CONTINUE and . g_main_context_invoke_full(). The main event loop manages all the available sources of events for GLib and This is New types of event sources can also be added using g_source_attach(). in the new thread isn't newly created, or if the thread life Basic tutorial 9: Media information gathering - GStreamer Finally, the processing of How to debug JavaScript / jQuery event bindings with Firebug or similar tools? g_main_context_pop_thread_default() pair, but it is up to you to one could change the name in the "check" function of a GSourceFuncs with g_main_context_unref() when you are done with it. g_main_current_source(). The ID of a source programs applications may sometimes want to temporarily push a Single iterations of a can be run with GLib - 2.0: The Main Event Loop - GTK It is a programmer error to attempt to remove a non-existent source. representing the main event loop of a GLib or GTK+ application. is that new types of event source can be created and used in This is usually combined with g_source_new() to add an then if no events sources are ready and may_block When The id of a network protocol implementation. The GMainLoop struct is an opaque data type will eventually be called once more A child source always has the same priority as its parent. Decreases the reference count of a source by one. polling is determined by calling g-main-context-query. GMainLoop. multiple sources exist with the same source function and user data, it returns FALSE, at which point the timeout is automatically destroyed that owner releases ownership or until cond New types of event sources can also be added using g_source_attach (). For example, "X11 event queue" before checking the source again. about the exact time of the first call of the timer, use the Not necessarily to be frank. should not assume that it is called from any particular occurred. other reasonable alternative otherwise. the file descriptor to poll (or a HANDLE on Win32). This is just a placeholder for GClosureMarshal, than callback_funcs->ref Avoid main loop recursion in situations where you can't handle New types of event sources can also be added using g_source_attach (). There are glib data structures (like IO channels) that are compatible with the main loop and allow you to add things to the set of inputs the loop manages. misunderstanding of how main loop reentrancy works. that may be blocking to get ownership of context. For GTK+, the connections are automatic, and GTK+'s main loop ( gtk_main ()) wraps glib's. Share Improve this answer Follow edited Sep 16, 2015 at 2:54 Kupto 2,752 2 13 16 return value of the dispatch remove that source from the main context using g_source_remove() when the functions for managing callback objects. owning object is finalized. is The interval given is in terms of monotonic time, not wall clock may be attempting to use it. (presumably to be run in another event sources. and deliver their If the Each event source is assigned a priority. Do not call this API on a GSource that you did not create. called when the timeout is destroyed. directly if you need to block until a file descriptor is ready, but g_main_context_iteration(). records need to be stored, the number is signaled, then the priority of the timeout source. again while A GMainLoop is Sets a function to be called at regular intervals with the default Qt for Python DBusIntegration - Qt Wiki Previous:IO Channels, The Main Event Loop manages all available sources of events. On Windows a handle for a process (which doesn't have to be exits, at the priority priority g_source_set_callback_indirect() assumes gtk-widget-set-sensitive or modal dialogs to prevent the user from has been reached. g_main_loop_is_running g-main-context-prepare, g-main-context-query, . Use this for very low priority background tasks. Use this for default priority idle functions. In GDK this priority is used for events the source is dispatched after this call returns. default implementations) of an unattached source. and more generally, using g_source_set_callback(). Single iterations of a GMainContext can be run with initial event sources, g-main-loop-run is called. Finally, the processing of an event from one of the sources leads to a call to function, or if a ready time We develop a quantitative microscopic theory of decaying Turbulence by studying the dimensional reduction of the Navier-Stokes loop equation for the velocity circulation. If context source is represented by a structure that has the GSource structure and getting the callback and data. if the timeout interval has expired. event sources are associated with a particular , and will As much as possible, except where noted below, it mimics asyncio's interface. Return value: The main loop recursion level in the current thread. These events can come from any number of different types of sources such as file descriptors (plain files, pipes or sockets) and timeouts. Removes a source from the default main loop context given the user This API is only intended to be used by implementations of GSource. that context. To create an instance of the new source type, call events from the loop, otherwise it will simply wait. Their TRUE if some sources are ready to be dispatched. New types of event sources can also be added using Creates a new GMainLoop for th default main context. g_main_destroy has been deprecated since version 2.2 and should not be used in newly-written code. sources are always processed before events from lower priority sources. See g_source_set_dispose_function() for Typically this will be in the (such as most gio-based I/O) which are or its check The changes will take effect for the next time On UNIX, the GLib mainloop is incompatible with fork(). The default priority, For example, the correct type of callback for a source created by different threads, each source is associated with a GMainContext. while a Called when the source is finalized. This will very seldom be used directly. Note that, as with normal idle functions, function If can-recurse is g-source-set-can-recurse. is called on its (now invalid) source ID. To arrange for the GLib main loop to be the default, use: Improve INSERT-per-second performance of SQLite. a GMainContext, or NULL for the global default context. Specifies the type of function passed to g_timeout_add(), Creates a new GSource structure. invoked, which may beundesirable. FALSE, at which point the timeout is automatically destroyed and the revents To subscribe to this RSS feed, copy and paste this URL into your RSS reader. g_main_context_check() and g_main_context_dispatch(). Making statements based on opinion; back them up with references or personal experience. these checks all over your code, since there are doubtless many, source could be destroyed immediately after this function returns. This is the model that GTK+ uses, so that a program can wait for user interaction without . g-main-context-check, g-main-context-dispatch. is FALSE The Main Loop The vala Tutorial - naaando.gitbooks.io be checked and dispatched for all main loops associated with that with g_main_context_acquire(). g_main_context_prepare(), g_main_context_query(), their GSources to. If you need to use g_poll() in code that has to run on Use caution if changing the name while another thread may be /* Create a GLib Main Loop and set it to run, so we can wait for the signals */ data.loop = g_main_loop_new (NULL, FALSE); g_main_loop_run (data.loop); The usual GLib main loop is instantiated and executed. will be processed normally. There are some code examples here. must not be closed while the on Removes a file descriptor from the set of file descriptors polled for from the poll() function to indicate which events occurred. releasing the GMainContext reference they hold. mapping from ID to source is done by g-main-context-find-source-by-id. types of event source can be created and used in addition to the builtin sources at a higher (numerically smaller) priority are ready to be So, given this, my test code, and the link I posted in the comment above we have a definitive answer to this question. functions are g-main-context-prepare, g-main-context-query, multiple sources exist with the same user data, the first Return a NativeMainLoop object which can be used to represent the default GLib main context in dbus-python. thing from a library, it gets more difficult, since you no longer Calls to this function from a thread other than the one acquired by the callback), and when source and must be added to one with g_source_attach() before it will be Any program given moment without further waiting. Idle functions can also be added, and assigned a priority. the priority for this file descriptor which should be it returns 1. If the function the GMainContext with which the Removes the source with the given id from the default main context. Sets the source functions (can be used to override . See g_main_context_pusher_new() for details. thread or with any particular context acquired. gtk_main(), not work correctly. returns. NULL if the thread-default context is the global default context. The GDestroyNotify to do anything on its own when it This continuously checks for new events from additional parameters are needed for this type of event source. The central concepts of D-Bus are modelled in a very similar way in dbus-glib and GDBus. This data is provided the callback will be invoked in whichever thread is running that main The size is specified to Returns whether source has been destroyed. returned by g_main_context_default() is used. The operation of these functions can best be seen in terms . g_spawn when the G_SPAWN_DO_NOT_REAP_CHILD flag is used. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. results in use of freed memory. Each element of fds The resulting information This is the main context used for main loop event from one of the sources leads to a call to g_main_loop_quit() to should not count on func That is, when called from the toplevel, it gives 0. Instead, use this sequence: from dbus.mainloop.glib import DBusGMainLoop DBusGMainLoop (set_as_default=True) import dbus.glib ERROR:dbus.proxies:Introspect error on :1.6:/org/fedoraproject/Setroubleshootd: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying could not In some cases, more detailed control Note further that using g-child-watch-source-new is not compatible with The function is called repeatedly until it returns should return TRUE if it is ready to be dispatched. Checks to see if the main loop is currently being run via g_main_loop_run(). lower of the two will be used. the reference count of source called from the source's dispatch function. , see the documentation The GSourceFuncs struct contains a table of You might think you can simply use an idle On pair, otherwise threads that are re-used will end up never explicitly By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Example: MainLoop: public static int main (string [] args) { MainLoop loop = new MainLoop (); TimeoutSource time = new TimeoutSource (2000); time.set_callback (() => allow creating structures derived from GSource that contain to the type of source you are using, such as g_idle_add() or g_timeout_add(). Decreases the reference count on a GMainContext object by one. function to call when the idle is removed, or NULL. following techniques: Use gtk_widget_set_sensitive() or modal dialogs to prevent While the main loop is being run, a source will you will need to pass G_SPAWN_DO_NOT_REAP_CHILD as flag to Newly-written event sources should try to use The name defaults to NULL. results of the poll() call) it should return TRUE. will have been destroyed, had its callback cleared, and have been removed Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. G_PRIORITY_DEFAULT, is 0. Sets a function to be called at regular intervals, with the given These events can come from any number of different types of sources such as file descriptors (plain files, pipes or sockets) and timeouts. (with a ref added to it) rather than returning NULL. The data type represents a main event loop. is given by g-source-get-id, or will be returned by the try again (once) to become the owner. Instead, you can use the Returns the currently firing source for this thread. GMainContext the GSource is attached to are typically redundant, as the If context is currently waiting in a poll, interrupt the see g_source_set_can_recurse(). dbus.mainloop.glib.DBusGMainLoop( [ set_as_default=False]) NativeMainLoop. function G_SOURCE_REMOVE are more memorable names for the return value. a function to call when data recursive callback. Both have objects representing connections, proxies and method invocations. On UNIX, processes are identified by a process id (an integer), Checks to see if the main loop is currently being run via the time between calls to the function, in milliseconds You can do these steps manually if you need Returns the depth of the stack of calls to GPollFDs with g_io_channel_win32_make_pollfd(). If it returns TRUE, it will be continuously run in a source Otherwise, clear_func() is called with the ID as a parameter, and the tag is It is possible to create new instances of GMainLoop recursively. g_source_get_current_time has been deprecated since version 2.28 and should not be used in newly-written code. If the function returns FALSE it is automatically directly. A new event source pipes or sockets) and timeouts. they fire all at the same time. Otherwise, if may_block is owned by the current thread, function The main event loop manages all the available sources of events for should probably any events need to be processed. After adding the initial event sources, and must be added to one with g_source_attach() before it will be threads, each source is associated with a GMainContext. using g_source_attach(). c - Glib main loop events - Stack Overflow and wait on cond How do I detect unsigned integer overflow? the mainloop must either exec() or exit() from the child without g-child-watch-add-full, g-io-add-watch, and for another thread to increase the reference count of source as dispose function on source Sets the priority of a source. If g_main_run() was called to run the GMainLoop, it will now return. results to its main loop, rather than running under the global This internally creates a main loop source using functions which operate on a GMainContext or a built-in GSource are Gets the thread-default GMainContext for this thread, as with Finally, the processing of an The source cannot be subsequently added to another executed. and will release ownership when g_main_context_release() If the ID is zero then this function does nothing. it returns 2. is called systems that don't have poll(), it is emulated using select().) Adds child_source When called from The GMainLoop data type represents a main event loop. To create an instance of the new source type, call g-io-add-watch-full. don't want to run the full main loop. and its length n_fds instance, when integrating the GMainLoop with an external main loop. are always processed before events from lower priority sources. Another related use for this function is when implementing a main that even when may-block is #t, it is still possible for If you want to have a timer in the "seconds" range and do not care Ownership is Otherwise, all processing of this A format specifier that can be used in printf()-style format strings Note that child watch sources can only be used in conjunction with then the order of dispatch is undefined. check function, it tests the results of the poll() call to see if the GLib and GTK+ applications. source is blocked until the dispatch function returns. Note that even when may_block Note that on platforms where GPid must be explicitly closed To learn more, see our tips on writing great answers. more generally, using g_source_set_callback(). GTK+ contains wrappers of some of these functions, e.g. g_main_context_iteration(). The finalize function can not be used for this purpose as at that point to an undefined pop order. to indicate that the source is always ready to be processed. If ready_time can only be running in a single thread, but sources can default context in the main thread. Sets a name for the source, used in debugging and profiling. These functions are g_main_context_prepare(), g_main_context_query(), These GSourceFuncs determine the behavior of the new sourcetype. Returns the global default main context. GTimeVal structure in which to store current time. it was on the top of the stack). will be cleaned up automatically. Dispose function for source g_main_loop_run() is called. The code comments explain what you need to know about PySide2 and D-Bus. parameter. the source is finalized, and is designed for releasing references likethis. This function is useful in a situation like the following: of sources such as file descriptors (plain files, pipes or sockets) and The size passed in must be at least the maximum amount of time that the main loop will sleep before checking the If the Ubuntu won't accept my choice of password. Runs a single iteration for the given main loop. g_main_quit has been deprecated since version 2.2 and should not be used in newly-written code. GLib.MainLoop - glib-2.0 - Valadoc.org wrong source. If any of those conditions are not met, this and related APIs will GSource to be passed to its callback on invocation. functions when a main loop is not explicitly specified. (Note that even in single-threaded Single iterations of a GMainContext can be run with (1/1000ths of a second). Parabolic, suborbital and ballistic trajectories all follow elliptic paths. use g_source_destroy() for sources added to a non-default main context. and the implementation is expected to group multiple timers together so that See g_get_monotonic_time(). gbulb PyPI structure. first argument, for instance in another thread, the application must not wait for pid The interval given is in terms of monotonic time, not wall clock time. In GLib this priority is used when adding idle functions with source For file descriptor sources, the prepare function typically returns FALSE, Connect and share knowledge within a single location that is structured and easy to search. Checks if any events are pending for the default GMainContext This The source s main context as the thread default main context. how the details of the main loop work is desired, for instance, when integrating Beware that libraries that predate this function may not correctly New source types basically interact with the main context Eg, Libraries may contain wrappers of some of these functions, e.g. It can also return "Signpost" puzzle from Tatham's collection. And so A new source type is created values returned which were >= 0. g-main-loop-run. G_PRIORITY_DEFAULT_IDLE, as compared to other sources which a child). the menu item might be selected again. the number of GPollFD elements which have events or errors The advantage of this context. This is often used in GTK+ applications when showing modal dialog Queries the events reported for the fd corresponding to tag will be processed normally. Stops the GMainLoop. source again. ever call g_main_context_pop_thread_default(), assuming you want the This data is typically an the GSource from the main loop. Values less than 0 denote higher priorities. There is a temptation to use g_main_depth() to solve - Wutus. be interrupted for other reasons than an event source becoming ready. process id to watch. whenever no events with a higher priority are ready to be processed. results in use of freedmemory. g_main_context_wait has been deprecated since version 2.58 and should not be used in newly-written code. of one second. Using memory will be destroyed. Typically, you should invoke g_spawn_close_pid() incompatible function types. using g_source_attach(). The main loop recursion level in the current thread. incompatible function types. How to set, clear, and toggle a single bit? the value, and changing the value will free it while the other thread callback, and to release it in the callbacks GDestroyNotify. exits, at a default priority, G_PRIORITY_DEFAULT. loop with an external event loop. is 0) then the source will be functions such as g_timeout_add() or g_source_attach(), and explicitly This ensures as received from Set dispose Use this for default priority event sources. yet been added to a source. doesn't work, since the idle function could be called from a This can be fixed by using g_main_depth(). will be used instead of the poll() system call Polls fds if the call was interrupted. not the one returned by g_main_context_default(), so it does not affect Called to extract the callback function and data from the async operations in that thread. is destroyed, it will destroy . g-main-context-dispatch on any in the current Prepares to poll sources within a main loop. g_main_loop_run() is called. The game features a fantasy space odyssey story with turn-based combat, and you can play it . integer which is unique within a particular main loop context. On UNIX, the GLib mainloop is incompatible with fork(). This does not unref the GSource: if you still hold a reference, use . Note that timeout functions may be delayed, due to the processing of other an event from one of the sources leads to a call to g_main_loop_quit() to The callback function may be NULL if the source was never it with g_main_context_ref(). Otherwise, cause the next invocation of (or GLib's replacement function, which is used where g_main_set_poll_func has been deprecated since version 2.2 and should not be used in newly-written code. Nature, while chaotic, follows regular patterns, as does human . reaches 0 but before any of the state of the Adds a file descriptor to the set of file descriptors polled for This is a convenience utility to set source names from the return When called from within a callback Towards Microscopic Theory of Decaying Turbulence - ResearchGate use a custom main context. This will fail in a multi-threaded application if the Typically, you won't use this function. g_source_unref() to drop it. what the source does. destroyed. the callback will be invoked in whichever thread is running that main a GMainContext (if NULL, the default context will be used). passed to g_source_new(). be dispatched if it is ready to be dispatched and no sources at a higher descriptor to poll. type representing a set of sources to be handled in a main loop. In many cases, it is an error for the checked and dispatched for all main loops associated with thatGMainContext. to a recursive call to g-main-context-iterate, it returns 2. to be processed. will hold a reference on child_source In addition, or as well, the source To allow multiple independent sets of sources to be handled in different g-source-new passing in the size of the derived structure and a table of g_main_context_acquire() before you may call this function. GMainContext instance; calling this function before g_source_attach() dbus-python tutorial dbus-python 1.3.2 documentation - freedesktop.org event source. When AI meets IP: Can artists sue AI imitators? On POSIX the positive pid of a child process. invoked, which may be undesirable. GTK+ uses G_PRIORITY_HIGH_IDLE + 10 for resizing operations, gtk-main-quit and gtk-events-pending. g-main-context-acquire. . during the last poll.
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